The present invention relates to surfactants useful in life science and industrial formulations. More particularly, the invention relates to surfactants of alkoxylated amine neutralized by aromatic sulfonic acid and pesticide formulations containing the same.
Alkylphenol ethoxylates (APEs) are a class of common industrial surfactants which are widely used in pesticide formulations. However, formulations containing APEs do not always provide the most desirable combination of design specifications, e.g. product efficacy, working parameters and cost. Traditional non-APE surfactant systems have not been readily adaptable substitutes for APE surfactants. For example, depending on the formulation requirements, calcium dodecylbenzesulfonate used in conjunction with fatty acid ethoxylates has proven to be an unacceptable APE substitute because of poor performance within one or more design parameters such as emulsion stability, acute toxicity, temporal and thermal stability, chemical and physical stability; solution, suspension or dilution dynamics, and viscosity and suspension stabilization. Phosphate esters, which are non-APE surfactants found in many types of formulations, suffer from long term stability problems due to undesirable transesterification and saponification reactions involving the mono-ester, di-ester, and free acid components of the surfactant mixture. The inability of industry to adapt existing technology to improve upon characteristics of surfactant systems containing APEs has prompted the development of entirely new line non-APE surfactant substitutes. The additional challenge faced by the scientific community has been to develop new non-APE substitutes which can be easily made from readily available and cost effective raw materials. Accordingly, there continues to be a need for other non-APE surfactant substitutes.
It has now been found that alkoxylated amine neutralized aromatic sulfonic acids are suitable as non-APE surfactant substitutes. The surfactants of the instant invention may be in the form of a surfactant salt compound, or composition containing one or more the surfactant compounds or salts. In one embodiment of the invention, the compositions containing the instant non-APE surfactants do not contain or are substantially free of alkylphenol ethoxylates (APEs). The surfactants of the instant invention are obtained from combining the appropriate aromatic sulfonic acid with the appropriate alkoxylated amine.